CVC vectors and population dynamics of Dilobopterus costalimai in Valencia orange of Corrientes, Argentina

BELTRÁN, V.M.; TAIARIOL, D.R.; CACERES, S.; ZUBRZYCKI, H.; PLOPER, L.D.; WILLINK, E.; AUGIER, L.

Wuhan

Congreso; 11th International Citrus Congress; 2008

Citrus Variegated Chlorosis (CVC) is an important disease of sweet oranges; its causal agent is Xylella fastidiosa, a xylem-limited gram negative bacterium transmitted by insect vectors (sharpshooters leafhoppers) (Hemiptera: Cicadellidae: Cicadellinae).  The vectors were studied in 5 sites in Corrientes: 1- Colonia Tres de Abril-Bella Vista, 2- Ambrosio-Saladas, 3- Monte Caseros, 4 and 5- Lomas Sur-Bella Vista, and the population dynamics of Dilobopterus costalimai was evaluated at INTA Bella Vista Experiment Station, in a grove of 784 plants of Valencia Late orange on Rangpur, by using yellow sticky traps replaced monthly.  Marked shoots of 0.5-1 cm (10 per plant, 64 plants) were measured weekly (length in cm) until they stopped growing and six months later the presence of symptoms was registered.  The species Dilobopterus costalimai Young, the most important CVC vector in Brazil, was present at all sites; the maximum values were obtained in fall-winter in all sites.  At the EEA Bella Vista, D. costalimai increased from December to May during 2002-2003 and 2004-2005.  When shooting was abundant and grew for longer periods in coincidence with abundant rainfall and average temperatures between 20ºC and 25ºC, a higher population level was observed and as a consequence the CVC symptoms increased six months later.  Molomea lineiceps Young, the other species trapped in high number was not studied, but another species in this genus is cited as potential vector in Brazil.  Species captured in lower number and considered vectors were Bucephalogonia xanthopis (Berg), Sonesimia grossa (Signoret) and Acrogonia sp.